View Full Version : Looking for advice on startup behavior - Kaypro 4/84 and Osborne 1A

Chris Hafner
March 15th, 2013, 08:18 AM
I just picked up a Kaypro 4/84 and an Osborne 1A and have not had much luck finding complete users guide scans online. I've found technical manuals and pieces of the users guides, but this is my very first experience with these machines or CP/M at all, and so what I'm looking for is pretty much what a brand new, computer-illiterate user would have wanted to know back in the early '80s. Pretty much - what sort of behavior would you expect out of these machines at startup?

First, the Kaypro. It starts up to the request to insert the bootable disk in drive A:, and the A: drive light is on. I put the disk in, and it spins ... and spins ... and spins. Setting aside the strong possibility that I wrote the image incorrectly - I'm more curious about the behavior. Is it expected that the Kaypro would just spin the disk forever, even if it doesn't like it as a bootable disk? I would have thought it would spin for a bit and then kick back a non-bootable disk error and stop until you try another disk. Also, is it normal that it would automatically start scanning the disk without even a keystroke to prompt it?

The reason I'm curious - I've used a cleaning disk to try to make sure the heads are clean, and I've been cranking out a few boot disks from Dave Dunfield's site, using his Kaypro 4/84 images, a 360KB drive, and his disk imaging software. Since it's reasonably complicated, I'm guessing I'm going to go through quite a few iterations of the settings in the software before hitting upon the magic combination, which I'm fine with. I just want to make sure I understand the machine's startup behavior and whether I can trust it to recognize a good boot disk when I eventually figure out how to produce one.

On the Osborne - I get the Osborne's version of the screen, but I don't get a drive light and even with a disk inserted, the door closed, and after hitting enter, the disk doesn't spin. I basically get no drive activity. Common sense would suggest that in normal behavior if I insert the disk and hit enter as suggested, the drive would at least try to read the disk, so I'm guessing I need to open 'er up and check the connections, etc. But I'm just not sure what the normal behavior is.

If anybody could take pity on the newbie and let me know what these machines typically do and don't do at startup, it'd help me enormously in understanding what's wrong (if anything) and when I'll know if I've got it fixed. Any advice would be much appreciated!

Chris Hafner

March 15th, 2013, 10:46 AM
Hi Chris.

I have both these machines.

I'm not sure about just how long the Kaypro keeps spinning with a bad disk. I'd have to drag mine out and try it. It should eventually give up if it can't read it but perhaps it can ALMOST read it. In other words very small amounts of data flow in...just enough to trigger retry after retry. That's one theory anyway.

As to the Osborne, nothing should happen until you press ENTER. Then the drive should start and software load. If this doesn't happen consider that the keyboard might not be working?


March 15th, 2013, 10:53 AM
From what I remember, both the Kaypro and Osborne only care that the disk is readable--there's no real check that the boot record is valid. Read a bogus boot record in and the system hangs--and the disk keeps spinning.

March 15th, 2013, 12:09 PM
ditto's on all the above.

On the Kaypro, take the cover off and see what number is written (usually on a white sticker) on the bios. which I think is a 24 pin at U34. Another 24 pin at U9 which should be the character rom. If the U34 is something other than 81-??? it could possibly have been converted to an advent or kayplus rom.
If it is, then you can find boot disks online for it. If it is a bone stock Kaypro I would try switching drives A&B. You'll have to switch the drive ID's.

On the Osborne if I remember correctly you shouldn't get anything on the screen except insert the disk and press enter.
Is it an Osborne 1 - tiny screen or Executive with bigger screen?

Chris Hafner
March 17th, 2013, 02:45 PM
Thanks, everybody - I'm hoping I get a bit more time to tinker today and tomorrow and will investigate and play with the drives.

Phogren, the Osborne is a 1A - tiny screen, but the second revision.

Tezza and Chuck(G), one interesting thing about the Kaypro's behavior is that the drive just spins and spins, even if it's just a cleaning disk in there. So even if there's not a readable disk or if there's no data coming in, it just keeps on spinning, seemingly indefinitely.

Thanks for the help all, hopefully I'll get it sorted out!

Chris Hafner

March 29th, 2013, 04:19 AM
just got a couple of 4's, and am having similar problems. have u solved yours yet?

April 5th, 2013, 11:03 AM
Re: the O1... you may have a keyboard issue if it's doing nothing after pressing enter. Press any other key and watch to see if the screen re-draws. If it doesn't then something's wrong in keyboard land. If you don't notice if it is redrawing the screen, hold down the space bar- if the keyboard is working, the whole screen will start flickering on most (all?) rom versions.